BEIJING — Ren Zhengfei, the founder of the Chinese technology giant Huawei, has accused the United States of having political motivations in leveling criminal charges against the company and his daughter, a top Huawei executive.

The comments, made in an interview with the BBC that was published Monday, mark a rhetorical escalation. Mr. Ren and the firm had previously declined to say much on the case, citing respect for the legal process. But he appears to be sharpening his language as a hearing nears on whether his daughter should be sent to the United States to stand trial.

“I object to what the U.S. has done,” Mr. Ren told the BBC. “This kind of politically motivated act is not acceptable.”

Late last month, the Justice Department unveiled sweeping charges against Huawei and its chief financial officer, Meng Wanzhou, outlining yearslong efforts by the Chinese firm to steal American industrial secrets, obstruct a criminal investigation and evade economic sanctions against Iran.

Ms. Meng, who is Mr. Ren’s elder daughter, was arrested in December by Canadian authorities acting at the request of the United States. She remains in Canada while awaiting a decision by its legal authorities about whether she will be extradited to the United States to face charges.

The criminal case against Huawei and Ms. Meng coincides with a campaign by American officials to pressure Western governments not to use Huawei’s equipment in their mobile networks. Washington has long held that the company’s networking gear could be used to help Beijing spy on Americans, charges that Huawei has consistently denied.

Relations between China and the United States have already been tense as efforts to resolve their monthslong trade war plod forward.

Mr. Ren, 74, has generally preferred to avoid the spotlight as he built Huawei into the world’s largest supplier of the equipment that enables modern telecommunications.

In an interview last month with a group of journalists from international news outlets, Mr. Ren said: “I trust that the legal systems of Canada and the United States are open, just and fair, and will reach a just conclusion. We will make our judgment after all the evidence is made public.”

Mr. Ren’s latest comments appear to be aimed at a Canadian audience. A Canadian judge is set in the coming weeks to hear arguments about whether Ms. Meng should be extradited.

One issue that is likely to factor into the Canadian authorities’ decision is whether her arrest was politically motivated. Chrystia Freeland, Canada’s foreign minister, has warned the United States not to use the extradition process to pursue political ends. And last month, John McCallum, Canada’s ambassador to China at the time, said Ms. Meng had a good chance of avoiding extradition because of remarks by President Trump, who had said he was willing to intervene if it would help secure a trade deal.